This new gadget shows exactly where you forgot to put sunblock

Sunscreenr, the sunblock detection gadget from Voxelight, aims to make the invisible visible and to save us from missing spots and potentially life-threatening skin damage, or at least a nasty sunburn. It takes about 15 minutes for the sun's ultra-violet rays to do their business on your unprotected skin. Sunblock is designed to either block or absorb those rays, keeping them from damaging your skin either way. (The Environmental Protection Agency reports that 1 million people in the U.S. are diagnosed with skin cancer each year.)